cleanup: move pkg/ to internal/

The internal/ directory in Go has a special meaning, and indicates that
those packages are not meant for external consumption. Ceph-CSI does
provide public APIs for other projects to consume. There is no plan to
keep the API of the internally used packages stable.

Closes: #903
Signed-off-by: Niels de Vos <ndevos@redhat.com>

internal/util/idlocker_test.go

@@ -0,0 +1,52 @@
+/*
+Copyright 2019 ceph-csi authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"testing"
+)
+
+// very basic tests for the moment
+func TestIDLocker(t *testing.T) {
+	fakeID := "fake-id"
+	locks := NewVolumeLocks()
+	// acquire lock for fake-id
+	ok := locks.TryAcquire(fakeID)
+
+	if !ok {
+		t.Errorf("TryAcquire failed: want (%v), got (%v)",
+			true, ok)
+	}
+
+	// try to acquire lock  again for fake-id, as lock is already present
+	// it should fail
+	ok = locks.TryAcquire(fakeID)
+
+	if ok {
+		t.Errorf("TryAcquire failed: want (%v), got (%v)",
+			false, ok)
+	}
+
+	// release the lock for fake-id and try to get lock again, it should pass
+	locks.Release(fakeID)
+	ok = locks.TryAcquire(fakeID)
+
+	if !ok {
+		t.Errorf("TryAcquire failed: want (%v), got (%v)",
+			true, ok)
+	}
+}